/**
 * Calculate drift between current and previous persona
 * Returns a drift score (0-1) indicating how much the persona has changed
 */
export async function calculatePersonaDrift(
  currentSummary: string,
  previousSummary: string,
): Promise<number> {
  // TODO: Implement drift calculation
  // Could use:
  // - Lexical similarity (jaccard, cosine)
  // - Semantic similarity (embedding comparison)
  // - Structural similarity (section-by-section comparison)

  // For now, return 0 (no drift)
  return 0;
}
